DAVIE, Fla. - Miami Dolphins offensive line coach Chris Foerster resigned Monday and said he was seeking medical help after video surfaced on social media that appeared to show him snorting three lines of a white powdery substance at a desk.

Hours after the 56-second video was posted on Facebook and Twitter, Foerster announced his departure in a statement released by the team.

“I am resigning from my position with the Miami Dolphins and accept full responsibility for my actions,” he said. “I want to apologize to the organization, and my sole focus is on getting the help that I need, with the support of my family and medical professionals.”

It’s unclear when or where the video was made, or how it became public. Foerster, 55, has been an NFL assistant since 1992 and joined coach Adam Gase’s staff in Miami last year.

“We were made aware of the video late last night and have no tolerance for this behavior,” the team said in a statement that accompanied Foerster’s resignation announcement. “After speaking with Chris this morning, he accepted full responsibility and we accepted his resignation effective immediately. Although Chris is no longer with the organization, we will work with him to get the help he needs during this time.”

Gase said he learned of the video late Sunday, soon after the Dolphins’ 16-10 victory over Tennessee.

“I don’t think I can say what my reaction was,” Gase said.

The coach said he phoned Foerster, who apologized. Gase declined to say whether Foerster volunteered to resign or was urged to quit.

“He’s disappointed, he’s upset, he’s mad at himself,” Gase said. “It’s not fun, especially when you’re close to somebody. But you’ve got to take the next step and move on.”

The NFL was reviewing the matter, league spokesman Brian McCarthy said.

Gase said he has known Foerster since 2008, when both were assistants with the San Francisco 49ers. Foerster joined the Dolphins shortly after Gase became head coach last year.

“Since I’ve been around him, he has always been a guy who just put his head down and worked,” Gase said. “He was here at 4 in the morning and worked as hard as he could for us.”

The video appears to show Foerster and the powdery substance on the desk. The man is holding a rolled-up $20 bill in his right hand and appears to adjust the camera with his left hand.

“Hey babe, miss you, thinking about you,” he says. “How about me going to a meeting and doing this before I go?”

He then snorts the substance into his nose though the $20 bill and notes “those big grains falling” as residue lands on the desk.

“What do you think, I’m crazy?” Foerster asks after snorting the second line. “Ah, no, babe.

“It’s going to be a while before we can do this again … “ he says, “But I think about you when I do it. I think about how much I miss you, how high we got together, how much fun it was. So much fun.”

Before snorting the final line he says, “Last little bit before I go to my meeting.”

Foerster’s offensive line has played poorly this season, and the Dolphins (2-2) rank last in the league in points and yards per game. They planned an announcement later regarding his successor.

“Any time you lose a really good coach, it’s not ideal,” Gase said. “But we’ll rally. We’ll find a way.”

The Dolphins lost quarterback Ryan Tannehill to a season-ending knee injury in training camp, and their was opener postponed because of Hurricane Irma. Foerster’s departure becomes the latest chapter in a turbulent season.

“That’s the NFL, man,” Gase said. “It’s a league of distractions. You move on.”